Organopolysiloxane-modified polysaccharide and process for producing the same

ABSTRACT

An organopolysiloxane-modified polysaccharide prepared by esterification reacting (A) an organopolysiloxane having residual carboxylic anhydride groups and (B) a polysaccharide having hydroxyl groups, wherein the organopolysiloxane is bonded to the polysaccharide through half ester groups, and a process for the preparation of organopolysiloxane-modified polysaccharide, in which component (A) and component (B) are subjected to an esterification reaction in the presence of (C) a non-protonic polar solvent. The organopolysiloxane-modified polysaccharide comprising polysaccharide and organopolysiloxane bonded thereto through half ester groups is novel. The process for the preparation of organopolysiloxane-modified polysaccharide permits introduction of organopolysiloxane into polysaccharide at a high introduction ratio.

TECHNICAL FIELD

The present invention relates to organopolysiloxane-modifiedpolysaccharides and to a process for their preparation. In particular,it relates to novel polysaccharides, in which the organopolysiloxanesare bonded to the polysaccharides through half ester groups, and to aprocess for the preparation of organopolysiloxane-modifiedpolysaccharides that permits introduction of organopolysiloxanes in thepolysaccharides at a high introduction ratio.

BACKGROUND ART

Polysaccharides bonded to organopolysiloxane are taught in JapaneseUnexamined Patent Application Publication No. Hei 7-70204. The suggestedpreparation processes include, for instance, a process, in whichcationized cellulose, hydroxyethyl cellulose, or chitosan are reactedwith a dimethylpolysiloxane having one of the ends of the molecularchain blocked by a glycidoxypropyl group. In addition, a process, inwhich an isocyanate-containing organopolysiloxane is reacted withcellulose or cellulose derivatives has been offered in JapaneseUnexamined Patent Application Publication No. Hei 9-136901, and aprocess, in which a diorganopolysiloxane having one of the ends of themolecular chain blocked by an epoxycyclohexylethyl group is reacted witha polysaccharide derivative soluble in organic solvents and containingcarboxyl groups are discussed in Japanese Unexamined Patent ApplicationPublication No. Hei 11-349601.

However, the problem with many of the above-described processes is thelow ratio of organopolysiloxane introduced into the polysaccharides.This results from the low reactivity between the startingorganopolysiloxane selected and the polysaccharides. While processes forisocyanate-containing organopolysiloxane can overcome this, they aredisadvantageous because of the need to use toxic compounds for increasedreactivity.

As a result of investigations into methods that could be used to prepareorganopolysiloxane-modified polysaccharides with a high ratio ofintroduction of organopolysiloxane without using toxic compounds such asisocyanate-containing organopolysiloxanes, etc., the present inventorsfound that hydroxyl groups in polysaccharides can undergo anesterification reaction with organopolysiloxanes containing residualcarboxylic anhydride groups.

Thus, the present invention provides novel polysaccharides, in which theorganopolysiloxanes are bonded to the polysaccharides through estergroups, and a process for the preparation of organopolysiloxane-modifiedpolysaccharides that permits introduction of organopolysiloxanes intopolysaccharides at a high introduction ratio.

DISCLOSURE OF THE INVENTION

The organopolysiloxane-modified polysaccharide of the present inventionis prepared by esterfication reacting (A) an organopolysiloxane havingresidual carboxylic anhydride groups and (B) a polysaccharide havinghydroxyl groups, wherein the organopolysiloxane is bonded to thepolysaccharide through half ester groups.

The process for the preparation of organopolysiloxane-modifiedpolysaccharide of the present invention comprises esterificationreacting;

-   -   (A) an organopolysiloxane having residual carboxylic anhydride        groups, and    -   (B) a polysaccharide having hydroxyl groups, in the presence of    -   (C) a non-protonic polar solvent.

DETAILED DESCRIPTION OF THE INVENTION

Component (A) in the present invention is an organopolysiloxane havingresidual carboxylic anhydride groups. Component (A) is exemplified byorganopolysiloxanes represented by the average unit formula of R¹ _(a)R²_(b)SiO_((4-a-b)2). In the formula, R¹ is a residual carboxylicanhydride group, exemplified by residual carboxylic anhydride groupsrepresented by the general formula:

residual carboxylic anhydride groups represented by the general formula:

residual carboxylic anhydride groups represented by the general formula:

residual carboxylic anhydride groups represented by the general formula:

and residual carboxylic anhydride groups represented by the generalformula:

Group R³ in the above-mentioned residual carboxylic anhydride groups isa divalent hydrocarbon group, exemplified by methylene, ethylene,propylene, or another alkylene groups; phenylene, xylylene, tolylene, oranother arylene groups; methylenephenylene, ethylenephenylene, oranother alkylene-arylene groups, with alkylene groups being preferable.In addition, group R⁴ in the above-mentioned residual carboxylicanhydride groups is a hydrogen atom or alkyl group, with the alkylgroups of R⁴ exemplified by methyl, ethyl, propyl, pentyl, and hexyl.Additionally, group R² in the formulas above is a hydrogen atom ormonovalent hydrocarbon group, with the monovalent hydrocarbon groups ofR² exemplified by methyl, ethyl, propyl, butyl, pentyl, and other alkylgroups; vinyl, allyl, butenyl, pentenyl, hexenyl, and other alkenylgroups; phenyl, tolyl, xylyl, and other aryl groups; benzyl, phenetyl,and other aralkyl groups, with alkyl and aryl groups being preferableand methyl and phenyl being especially preferable. In addition, althoughgroup R² in the formulas above is a hydrogen atom or monovalenthydrocarbon group, hydrogen atoms cannot be used for all groups R².Also, the subscripts “a” and “b” in the formulas above are numberssatisfying the conditions 0<a≦1 and 0<b≦3, respectively, as well assatisfying the condition 0<a+b<4. In the formulas above, a+b ispreferably a number that satisfies the condition 0.5<a+b<3, andespecially preferably, 0.8<a+b<2.5.

There are no limitations concerning component (A) in terms of its themolecular structure, which is exemplified by linear, partially branchedlinear, branched, cyclic, and dendritic structures, with linearstructures being preferable. Such organopolysiloxanes are exemplified byorganopolysiloxanes represented by the general formula:

organopolysiloxanes represented by the general formula:

and organopolysiloxanes represented by the general formula:

Group R¹ in the formulas above are residual carboxylic anhydride groupsexemplified by the same groups as those mentioned above. In addition,group R² in the formulas above is a hydrogen atom or monovalenthydrocarbon group, with the monovalent hydrocarbon groups of R²exemplified by the same groups as those mentioned above. In addition,although group R² in the formulas above is a hydrogen atom or monovalenthydrocarbon group, hydrogen atoms cannot be used for all groups R². Inaddition, the subscript “n” in the formulas above is an integer of 0 orgreater. Also, the subscript “c” in the formula above is an integer of 1to 4.

Component (B) is a polysaccharide having hydroxyl groups. Component (B)can be any polysaccharide having hydroxy groups, but typically is chosento be able to be used in the esterification reaction with theabove-described component (A). There are no limitations concerning thebinding position of the hydroxyl groups in component (B). Component (B)is exemplified by cellulose, hemicellulose, and other ligneouspolysaccharides; gum arabic, gum tragacanth, adhesive juice of Hibiscusmanihot L., and other adhesive substances derived from plants; pectin,starch, konjak flour paste, mannan, and other fruit flesh andrhizome-derived polysaccharides; guar gum, locust bean gum, tamarindgum, quince seed gum, and other polysaccharides obtained from legumes;carrageenan, agar-agar, and other polysaccharides from seaweed; xanthangum, dextran, pullulan, levan, and other polysaccharide produced bymicroorganisms; chitin, hyaluronic acid, and other polysaccharides ofanimal origin; and polysaccharide derivatives obtained by subjectingsome of the hydroxyl groups of these polysaccharides tocarboxymethylation, sulfation, addition of alkylene oxides, such asethylene oxide and propylene oxide, acylation, cationation, andmolecular weight reduction.

In the organopolysiloxane-modified polysaccharides of the presentinvention, the organopolysiloxane residual groups supplied by theabove-described component (A) are bonded to the polysaccharide throughhalf ester groups. The half ester groups are exemplified by half estergroups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

half ester groups represented by the general formula:

and half ester groups represented by the general formula:

Group R³ in the formulas above is a divalent hydrocarbon groupexemplified by the same groups as those mentioned above. In addition,group R⁴ in the formulas above is a hydrogen atom or alkyl group, withthe alkyl groups exemplified by the same groups as those mentionedabove.

In the process of the present invention, (A) the carboxylic anhydridegroups of an organopolysiloxane and (B) the hydroxyl groups of apolysaccharide are subjected to an esterification reaction in thepresence of (C) a non-protonic polar solvent. There are no limitationsconcerning component (A) so long as it is an organopolysiloxane havingresidual carboxylic anhydride groups in the molecule. More specifically,it is exemplified by organopolysiloxanes represented by the average unitformula:R¹ _(a)R² _(b)SiO_((4-a-b)/2)In the formula above, group R¹ is a residual carboxylic anhydride groupexemplified by the same groups as those mentioned above. Also, group R²in the formula above is a hydrogen atom or monovalent hydrocarbon group,with the monovalent hydrocarbon groups of R² exemplified by the samegroups as those mentioned above. In addition, although R² in the formulaabove is a hydrogen atom or monovalent hydrocarbon group, hydrogen atomscannot be used for all R². Also, the subscripts “a” and “b” in theformula above are numbers satisfying the conditions 0<a≦1 and 0<b≦3,respectively, as well as satisfying the condition 0<a+b<4. In theformula above, a+b is preferably a number that satisfies the condition0.5<a+b<3, and especially preferably, 0.8<a+b<2.5.

There are no limitations concerning the molecular structure of component(A), which is exemplified by linear, partially branched linear,branched, cyclic, and dendritic structures, with linear structures beingpreferable. Component (A) is exemplified by the same organopolysiloxanesas those mentioned above.

Process used for preparing component (A) are known in the art and areexemplified by the following.

-   -   (1) A process, in which an organopolysiloxane containing        silicon-bonded hydrogen atoms is subjected to an addition        reaction with norbornenedicarboxylic anhydride (see U.S. Pat.        No. 4,381,196).    -   (2) A process, in which a 1,3-bis(dimethylphenyl)disiloxane        derivative is subjected to oxidation (see Japanese Unexamined        Patent Application Publication No. Sho 63-270690 and Japanese        Unexamined Patent Application Publication No. Sho 63-316790).    -   (3) A process, in which an organopolysiloxane containing        cyclopentadienyl groups is subjected to a Diels-Alder reaction        with maleic anhydride (see Chemical Abstracts, 72, 32777        (1970)).    -   (4) A process, in which an organopolysiloxane containing        silicon-bonded hydrogen atoms is subjected to an addition        reaction with 1,4-dichlorobutyne in the presence of a platinum        catalyst and the reaction product is reduced with zinc to        2-silyl-substituted-1,3-butadiene, which is subsequently        subjected to a Diels-Alder reaction with maleic anhydride (see        European Pat. No. 176085).    -   (5) A process, in which an organopolysiloxane containing        silicon-bonded hydrogen atoms is subjected to an addition        reaction with alkyl alcohol in the presence of a platinum        catalyst and the reaction product is heated with maleic        anhydride, generating a diene by means of a dehydration        reaction, which is followed by a Diels-Alder reaction (see        Japanese Unexamined Patent Application Publication No. Hei        3-109428).    -   (6) A process, in which a butadienyl-containing        organopolysiloxane is obtained by reacting 2-halogenated        magnesium- 1,3-butadiene with a halosilyl-containing        organopolysiloxane and the product is subjected to a Diels-Alder        reaction with maleic anhydride (Japanese Unexamined Patent        Application Publication No. Hei 4-211091).    -   (7) A process, in which cyclopentadienylalkyl-containing        disiloxane is subjected to a Diels-Alder reaction with maleic        anhydride (Japanese Unexamined Patent Application Publication        No. Hei 4-89492).    -   (8) A process, in which an organopolysiloxane containing        silicon-bonded hydrogen atoms is subjected to an addition        reaction with an alkenyl-containing succinic anhydride (Japanese        Unexamined Patent Application Publication No. Hei 5-331291).

In addition, there are no limitations concerning component (B) so longas it is a polysaccharide having hydroxyl groups in the molecule.Specifically, it is exemplified by the same polysaccharides as the onesmentioned above, with cationized cellulose represented by the generalformula:

being the most preferable compound. In the formula above, the subscripts“p” and “q” are numbers respectively satisfying the conditions 0≦p≦2000and 5≦q≦3000.

Typically, due to the low compatibility of component (A) and component(B), in the preparative process of the present invention, theesterification reaction is carried out in the presence of (C) anon-protonic polar solvent in order to enhance their compatibility andimprove reactivity. Component (C) is exemplified byN,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, andhexamethylphosphortriamide. In addition, component (C) can be used incombination with other non-protonic organic solvents that essentially donot react with component (B) and component (A). The non-protonic organicsolvents are exemplified by benzene, toluene, xylylene, and otheraromatic hydrocarbons; hexane, pentane, and other aliphatichydrocarbons; tetrahydrofuran, diethyl ether, and other ethers; acetone,methyl ethyl ketone, methyl isobutyl ketone, and other ketones.

Additionally, in the preparative process of the present invention, thereare no limitations concerning the reaction temperature. Although theesterification reaction can be carried out at room temperature, heatingis preferable. In case of heating, the reaction temperature shouldpreferably be in the range of from 50° C. to 150° C., and especiallypreferably, in the range of from 60° C. to 110° C. If component (B)contains a large amount of moisture, the moisture may react with thecarboxylic anhydride groups in component (A) and its reactivity with thehydroxyl groups in component (B) may decrease. For this reason, in thepreparative process of the present invention, it is desirable to removeas much moisture from component (B) as possible in advance.

In the preparative process of the present invention, after subjectingcomponent (A) and component (B) to an esterification reaction, anorganic solvent, which is a good solvent for unreacted component (A) anda poor solvent for unreacted component (B) and the reaction product, isintroduced in the system to precipitate the reaction product and, afterwashing with solvent, the unreacted component (A) can be removed byfiltration or other methods and an organopolysiloxane-modifiedpolysaccharide, i.e. the target reaction product, can be separated bydrying under heating and reduced pressure.

EXAMPLES

The organopolysiloxane-modified polysaccharides of the present inventionand the process of their preparation will be now explained in detail byreferring to application examples.

Reference Example 1

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 25 g ofdimethylpolysiloxane represented by the formula:

(silicon-bonded hydrogen atoms=24.1 millimol) under a nitrogenatmosphere, the mixture was heated to 80° C. and 3.38 g (24.1 millimol)of allylsuccinic anhydride were added thereto in a dropwise manner. Upontermination of the dropwise addition, the mixture was stirred for 5hours at a temperature within the range of from 80° C. to 100° C.Subsequently, 27.2 g of a polymer were obtained by eluting low-boilingfractions by heating under reduced pressure. A nuclear magneticresonance analysis (referred to as NMR below) and infrared spectroscopyanalysis (referred to as IR below) of the polymer found that it was adimethylpolysiloxane represented by the formula:

Reference Example 2

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 25 g ofdimethylpolysiloxane represented by the formula:

(silicon-bonded hydrogen atoms=30.5 millimol) under a nitrogenatmosphere, the mixture was heated to 80° C. and 3.38 g (30.5 millimol)of allylsuccinic anhydride were added thereto in a dropwise manner. Upontermination of the dropwise addition, the mixture was stirred for 5hours at a temperature within the range of from 80° C. to 100° C.Subsequently, 27.2 g of a polymer were obtained by eluting low-boilingfractions by heating under reduced pressure. An NMR and IR analysis ofthe polymer found that it was a dimethylpolysiloxane represented by theformula:

Reference Example 3

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 2.23 g of2-methyl-3-butyn-2-ol (26.5 millimol) under a nitrogen atmosphere, themixture was heated to 100° C. and 25 g (silicon-bonded hydrogenatoms=24.1 millimol) of dimethylpolysiloxane represented by the formula:

were added thereto in a dropwise manner. Upon termination of thedropwise addition, the mixture was stirred for 1.5 hours at 110° C.,whereupon it was determined by an IR analysis that the absorption of thesilicon-bonded hydrogen atoms had disappeared. Subsequently, excess2-methyl-3-butyn-2-ol and other low-boiling fractions were eluted byheating under reduced pressure, yielding 26.1 g of polymer. An NMR andIR analysis of the polymer found that it was a dimethylpolysiloxanemixture made up of a dimethylpolysiloxane represented by the formula:

and a dimethylpolysiloxane represented by the formula:

combined in a molar ratio of 7:3.

Next, 20 g of the dimethylpolysiloxane mixture, 1.86 g (19.0 millimol)of maleic anhydride, 0.55 milligrams of sulfuric acid, and 20milliliters of toluene were introduced in the system and reacted for 4hours at a temperature within the range of from 140° C. to 150° C. whilesubjecting the water produced in the reaction to azeotropic dehydration.After cooling, the solution was neutralized with 1.1 milligrams oftriethylamine and the salts of neutralization were filtered off alongwith crystallized unreacted maleic anhydride. Then, 20.9 g of a polymerwere obtained by eluting the low-boiling fractions of the filtrate byheating under reduced pressure. An NMR and IR analysis of the polymerfound that it was a dimethylpolysiloxane mixture made up of adimethylpolysiloxane represented by the formula:

and a dimethylpolysiloxane represented by the formula:

combined in a molar ratio of 7:3.

Reference Example 4

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 2 g of2-methyl-3-butyn-2-ol (23.8 millimol) under a nitrogen atmosphere. Themixture was heated to 100° C. and 17.7 g dimethylpolysiloxanerepresented by the formula:

(silicon-bonded hydrogen atoms=21.6 millimol) were added thereto in adropwise manner. Upon termination of the dropwise addition, the mixturewas stirred for 1.5 hours at 110° C., whereupon it was determined by anIR analysis that the absorption of the silicon-bonded hydrogen atoms haddisappeared. Subsequently, excess 2-methyl-3-butyn-2-ol and otherlow-boiling fractions were eluted by heating under reduced pressure,yielding 19.0 g of polymer. An NMR and IR analysis of the polymer foundthat it was a mixture of dimethylpolysiloxanes represented by theformula:

in which groups X¹ were groups represented by the formula:

and groups represented by the formula:

in a molar ratio of 7:3.

Next, 15 g of the dimethylpolysiloxane mixture, 3.26 g (33.2 millimol)of maleic anhydride, 0.55 milligrams of sulfuric acid, and 6.5milliliters of xylene were introduced in the system and reacted for 4hours at a temperature within the range of from 140° C. to 150° C. whilesubjecting the water produced in the reaction to azeotropic dehydration.After cooling, the solution was neutralized with 1.1 milligrams oftriethylamine and the salts of neutralization were filtered off alongwith crystallized unreacted maleic anhydride. The, 15.2 g of a polymerwere obtained by eluting the low-boiling fractions of the filtrate byheating under reduced pressure. An NMR and IR analysis of the polymerfound that it was a mixture of dimethylpolysiloxanes represented by theformula:

in which groups X² were residual carboxylic anhydride groups representedby the formula:

and residual carboxylic anhydride groups represented by the formula:

in a molar ratio of 7:3.

Reference Example 5

An equilibration reaction was conducted by introducing 14.8 g (50millimol) of octamethylcyclotetrasiloxane, 1.12 g (8.3 millimol) of1,1,3,3-tetramethyldisiloxane, 1.35 g (8.3 millimol) ofhexamethyldisiloxane, and 2 wt % of activated clay serving as a catalystin the system under a nitrogen atmosphere and subjecting the mixture toagitation for 2 hours under heating at 40° C., followed by another twohours of agitation under heating at 65° C. Subsequently, after coolingthe mixture to room temperature, the activated clay was filtered off,yielding 16.5 g of polymer. It was found that the polymer was a mixtureof dimethylpolysiloxanes (content of silicon-bonded hydrogen atoms=0.087wt %) represented by the average formula:

in which groups X³ were made up of hydrogen atoms and methyl groups.

Reference Example 6

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 22.9 g of of thedimethylpolysiloxane mixture prepared in Reference Example 5(silicon-bonded hydrogen atoms=20 millimol), the mixture was heated to80° C. and 2.80 g (20 millimol) of allylsuccinic anhydride were addedthereto in a dropwise manner. Upon termination of the dropwise addition,the mixture was stirred for 5 hours at a temperature within the range offrom 80° C. to 100° C. Subsequently, 24.2 g of a polymer were obtainedby eluting low-boiling fractions by heating under reduced pressure. AnNMR and IR analysis of the polymer found that it was a mixture ofdimethylpolysiloxanes represented by the average formula:

in which groups X⁴ were made up of methyl groups and residual carboxylicanhydride groups represented by the formula:

Reference Example 7

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 5 ppm of platinum metal relative to the totalweight of the reaction starting materials) was added to 1.85 g of2-methyl-3-butyn-2-ol. The mixture was heated to 100° C. and 22.9 g(silicon-bonded hydrogen atoms=20 millimol) of the dimethylpolysiloxanemixture prepared in Reference Example 5 were added thereto in a dropwisemanner. Upon termination of the dropwise addition, the mixture wasstirred for 1.5 hours at 110° C., whereupon it was determined by an IRanalysis that the absorption of the silicon-bonded hydrogen atoms haddisappeared. Subsequently, 23.1 g of a polymer were obtained by elutingexcess 2-methyl-3-butyn-2-ol and other low-boiling fractions by heatingunder reduced pressure. An NMR and IR analysis of the polymer found thatit was a mixture of dimethylpolysiloxanes represented by the averageformula:

in which groups X⁵ were made up of methyl groups, groups represented bythe formula:

and groups represented by the formula:

Subsequently, 22 g of the dimethylpolysiloxane mixture, 1.86 g (19millimol) of maleic anhydride, 0.55 milligrams of sulfuric acid, and 6.5milliliters of xylylene were introduced in the system and reacted for 4hours at a temperature within the range of from 140° C. to 150° C. whilesubjecting the water produced in the reaction to azeotropic dehydration.After cooling, the solution was neutralized with 1.1 milligrams oftriethylamine and the salts of neutralization were filtered off alongwith crystallized unreacted maleic anhydride. 15.2 g of a polymer wereobtained by eluting the low-boiling fractions of the filtrate by heatingunder reduced pressure. An NMR and IR analysis of the polymer found thatit was a mixture of dimethylpolysiloxanes represented by the averageformula:

in which groups X⁶ were made up of methyl groups, residual carboxylicanhydride groups represented by the formula:

and residual carboxylic anhydride groups represented by the formula:

Reference Example 8

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient to provide 50 ppm of platinum metal relative to the totalweight of the reaction starting materials) and toluene (an amountsufficient to provide a concentration of 5 wt % relative to the totalweight of the starting materials) were added to 11.4 g (silicon-bondedhydrogen atoms=10 millimol) of the dimethylpolysiloxane mixture preparedin Reference Example 5. The mixture was heated to 100° C. and 1.72 g(10.5 millimol) of 5-norbornene-2,3-dicarboxylic anhydride were addedthereto in a dropwise manner. Upon termination of the dropwise addition,the mixture was stirred for 7 hours at a temperature within the range offrom 130° C. to 150° C. Subsequently, 12.4 g of a polymer were obtainedby means of eluting low-boiling fractures by heating under reducedpressure and filtering off unreacted 5-norbornene-2,3-dicarboxylicanhydride. An NMR and IR analysis of the polymer found that it was amixture of dimethylpolysiloxanes represented by the average formula:

in which groups X⁷ were made up of methyl groups and residual carboxylicanhydride groups represented by the formula:

Reference Example 9

A complex of platinum and 1,3-divinyltetramethyldisiloxane (an amountsufficient o provide 5 ppm of platinum metal relative to the totalweight of the starting materials) as added to 19 g of organopolysiloxanerepresented by the formula:

(silicon-bonded hydrogen atoms=32.7 millimol) under a nitrogenatmosphere. Next, the mixture was heated to 80° C. and 4.6 g (32.7millimol) of allylsuccinic anhydride were added thereto in a dropwisemanner. Upon termination of the dropwise addition, the mixture wasstirred for 5 hours at a temperature within the range of from 80° C. to100° C. Subsequently, 12.8 g of a polymer were obtained by elutinglow-boiling fractions by heating under reduced pressure. An NMR and IRanalysis of the polymer found that it was an organopolysiloxanerepresented by the formula:

Application Example 1

0.05 g of the dimethylpolysiloxane prepared in Reference Example 1(residual carboxylic anhydride groups=0.043 millimol), 1.0 g of driedcationized cellulose represented by the formula:

and 10 g of N,N-dimethylacetamide were mixed and the mixture was stirredfor 3 hours at 40° C. After cooling, the mixture was combined with 20milliliters of isopropyl alcohol and filtered. Subsequently, 0.99 g of awhite powder were obtained by thoroughly washing the filter cake withisopropyl alcohol and drying it in a vacuum oven. An IR analysis of thewhite powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane prepared in Reference Example 1, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

In addition, fluorescent X-ray analysis found that thedimethylpolysiloxane content in the dimethylpolysiloxane-modifiedcationized cellulose was 2.71 wt % and the degree of substitution,defined as the number of dimethylpolysiloxane units introduced per 1glucose unit, was 2.0×10⁻².

Application Example 2

0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (carboxylic anhydridegroups=0.053 millimol) of the dimethylpolysiloxane prepared in ReferenceExample 2 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane prepared in Reference Example 2, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 6.14 wt %and the degree of substitution was 2.9×10⁻².

Application Example 3

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (carboxylic anhydridegroups=0.041 millimol) of the dimethylpolysiloxane mixture prepared inReference Example 3 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane mixture prepared in Reference Example 3, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

as well as by half ester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 0.69 wt %and the degree of substitution was 4.4×10⁻³.

Application Example 4

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (residual carboxylic anhydridegroups=0.051 millimol) of the dimethylpolysiloxane mixture prepared inReference Example 4 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane mixture prepared in Reference Example 4, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

as well as by half ester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 2.88 wt %and the degree of substitution was 1.2×10⁻².

Application Example 5

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (residual carboxylic anhydridegroups=0.039 millimol) of the dimethylpolysiloxane mixture prepared inReference Example 6 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane mixture prepared in Reference Example 6, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 1.55 wt %and the degree of substitution was 1.0×10⁻².

Application Example 6

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (residual carboxylic anhydridegroups=0.039 millimol) of the dimethylpolysiloxane mixture prepared inReference Example 7 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane mixture prepared in Reference Example 7, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

as well as by half ester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 0.67 wt %and the degree of substitution was 4.7×10⁻³.

Application Example 7

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (residual carboxylic anhydridegroups=0.039 millimol) of the dimethylpolysiloxane mixture prepared inReference Example 8 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane mixture prepared in Reference Example 8, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedcationized cellulose, in which the dimethylpolysiloxane was bonded tothe cationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized cellulose was 1.14 wt %and the degree of substitution was 7.3×10⁻³.

Application Example 8

First, 0.99 g of a white powder were obtained in the same manner as inApplication Example 1, except that 0.05 g (residual carboxylic anhydridegroups=0.069 millimol) of the organopolysiloxane prepared in ReferenceExample 9 were used in Application Example 1 instead of thedimethylpolysiloxane prepared in Reference Example 1. An IR analysis ofthe white powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the organopolysiloxane mixture prepared in Reference Example 9, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was an organopolysiloxane-modifiedcationized cellulose, in which the organopolysiloxane was bonded to thecationized cellulose through half ester groups represented by theformula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the content of theorganopolysiloxane in the organopolysiloxane-modified cationizedcellulose was 0.7 wt % and the degree of substitution was 1.5×10⁻².

Application Example 9

First, 0.1 g of the dimethylpolysiloxane prepared in Reference Example 1(residual carboxylic anhydride groups=0.085 millimol), 1.0 g ofhydroxyethyl cellulose (a 2 wt % aqueous solution of which had aviscosity of between 200 mPa.s and 300 mPa.s at 20° C.), and 10 g ofN,N-dimethylacetamide were mixed and the mixture was stirred for 3 hoursat 40° C. After cooling, the mixture was combined with 20 milliliters ofisopropyl alcohol and filtered. Then, 0.98 g of a pale brown laminarsubstance were obtained by thoroughly washing the filter cake withisopropyl alcohol and drying it in a vacuum oven. An IR analysis of thepale brown laminar substance found that peaks in the vicinity of 1790cm⁻¹ and 1870 cm⁻¹, which were indicative of the residual carboxylicanhydride groups in the dimethylpolysiloxane prepared in ReferenceExample 1, had disappeared and new peaks appeared in the vicinity of1730 cm⁻¹ and 1620 cm⁻¹, confirming that the product was adimethylpolysiloxane-modified hydroxyethyl cellulose, in which thedimethylpolysiloxane was bonded to the hydroxyethyl cellulose throughhalf ester groups represented by the formula:

and/or half ester groups represented by the formula:

In addition, fluorescent X-ray analysis found that thedimethylpolysiloxane content in the dimethylpolysiloxane-modifiedhydroxyethyl cellulose was 1.47 wt % and the degree of substitution was2.2×10⁻³.

Application Example 10

First, 0.99 g of a pale brown laminar substance were obtained in thesame manner as in Application Example 9, except that 1.0 g ofhydroxypropyl cellulose (a 2 wt % aqueous solution of which had aviscosity of between 150 mPa.s and 400 mPa.s at 20° C.) was used inApplication Example 9 instead of the hydroxyethyl cellulose. An IRanalysis of the pale brown laminar substance found that peaks in thevicinity of 1790 cm⁻¹ and 1870 cm⁻¹, which were indicative of theresidual carboxylic anhydride groups in the dimethylpolysiloxaneprepared in Reference Example 1, had disappeared and new peaks appearedin the vicinity of 1730 cm⁻¹ and 1620 cm⁻¹, confirming that the productwas a dimethylpolysiloxane-modified hydroxypropyl cellulose, in whichthe dimethylpolysiloxane was bonded to the hydroxypropyl cellulosethrough half ester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified hydroxypropyl cellulose was 1.62 wt% and the degree of substitution was 2.6×10⁻³.

Application Example 11

First, 0.98 g of a yellowish powder were obtained in the same manner asin Application Example 9, except that 1.0 g of chitosan (an aqueoussolution of 0.5 wt % acetic acid and 0.5 wt % chitosan had a viscosityof between 5 mPa.s and 20 mPa.s at 20° C.; in addition, the degree ofdeacetylation was not less than 80.0 mol/mol %) was used in ApplicationExample 9 instead of the hydroxyethyl cellulose. An IR analysis of theyellowish powder found that peaks in the vicinity of 1790 cm⁻¹ and 1870cm⁻¹, which were indicative of the residual carboxylic anhydride groupsin the dimethylpolysiloxane prepared in Reference Example 1, haddisappeared and new peaks appeared in the vicinity of 1730 cm⁻¹ and 1620cm⁻¹, confirming that the product was a dimethylpolysiloxane-modifiedchitosan, in which the dimethylpolysiloxane was bonded to the chitosanthrough half ester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified chitosan was 0.85 wt % and thedegree of substitution was 9.1×10⁻⁴.

Application Example 12

First, 0.99 g of a pale yellow powder were obtained in the same manneras in Application Example 7, except that 1.0 g of cationized guar gum (a1 wt % aqueous solution of which had a viscosity of 3500 mPa.s at 20°C.) was used in Application Example 7 instead of the cationizedcellulose. An IR analysis of the pale yellow powder found that peaks inthe vicinity of 1790 cm⁻¹ and 1870 cm⁻¹, which were indicative of theresidual carboxylic anhydride groups in the dimethylpolysiloxaneprepared in Reference Example 8, had disappeared and new peaks appearedin the vicinity of 1730 cm⁻¹ and 1620 cm⁻¹, confirming that the productwas a dimethylpolysiloxane-modified cationized guar gum, in which thedimethylpolysiloxane was bonded to the cationized guar gum through halfester groups represented by the formula:

and/or half ester groups represented by the formula:

Fluorescent X-ray analysis found that the dimethylpolysiloxane contentin the dimethylpolysiloxane-modified cationized guar gum was 0.94 wt %and the degree of substitution was 1.2×10⁻³.

Comparative Example 1

First, 20 g of cationized cellulose (obtained by an addition reactionbetween hydroxyethyl cellulose and glycidyltrimethylammonium chloride)were dispersed in a solution containing 20 g water, 0.3 g sodiumhydroxide, 8 g of an organopolysiloxane represented by the formula:

and 80 g isopropyl alcohol. A dispersion was prepared by stirring thesolution for 5 hours under heating at 50° C., whereupon the dispersionwas cooled to room temperature and filtered to recovering solid matter,which was then dissolved in 180 g water and the solution wasneutralized. The product was precipitated by adding 500 milliliters ofisopropyl alcohol and, after washing it with isopropyl alcohol, a whitepowder was obtained by drying. An IR analysis of the white powder foundthat it was a dimethylpolysiloxane-modified cationized cellulose, inwhich the dimethylpolysiloxane was bonded to the cationized cellulosethrough ether bonds. The average molecular weight of thedimethylpolysiloxane-modified cationized cellulose was about 150,000,the dimethylpolysiloxane content was 2.1 wt %, and the degree ofsubstitution was 6.8×10⁻⁴.

Industrial Applicability

The organopolysiloxane-modified polysaccharide of the present invention,wherein the organopolysiloxane is bonded to the polysaccharide throughhalf ester groups, is novel. And the process for the preparation oforganopolysiloxane-modified polysaccharide of the present inventionpermits introduction of organopolysiloxane into the polysaccharide at ahigh introduction ratio without using toxic compounds such asisocyanate-containing organopolysiloxanes, etc.

Such organopolysiloxane-modified polysaccharide of the present inventionis useful in a wide range of applications such as in papermaking,coatings, ceramics, construction, civil engineering, agriculture,aquaculture, fibers, food products, medicines, perfumery and cosmetics,and other fields as pressure-sensitive adhesives, dispersing agents,protective colloid agents, spreaders, thickeners, granulating agents,water-retaining agents, film-forming agents, carriers for functionalcomponents, etc.

1. An organopolysiloxane-modified polysaccharide prepared by a processcomprising the step of esterfication reacting (A) an organopolysiloxanehaving residual carboxylic anhydride groups and (B) a polysaccharidehaving hydroxyl groups, wherein the organopolysiloxane is bonded to thepolysaccharide through half ester groups.
 2. Theorganopolysiloxane-modified polysaccharide according to claim 1, whereincomponent (A) is an organopolysiloxane having the formula, R¹ _(a)R²_(b)SiO_((4-a-b)/2) where R¹ is a monovalent organic group containing aresidual carboxylic anhydride, R² is a hydrogen atom or monovalenthydrocarbon group with the proviso that at least one R² is a monovalenthydrocarbon when b is greater than 1, and the subscripts “a” and “b” arenumbers satisfying the conditions 0<a≦1, and 0<b≦3, respectively, and0a+b<4.
 3. The organopolysiloxane-modified polysaccharide according toclaim 1, wherein component (A) is an organopolysiloxane having theformula selected from the group of;

where R¹ is a monovalent organic group containing a residual carboxylicanhydride group, R² is a hydrogen atom or monovalent hydrocarbon group,with the proviso that at least one R² is a monovalent hydrocarbon, n isan integer greater than zero, and c is an integer from 1 to
 4. 4. Theorganopolysiloxane-modified polysaccharide according to claim 2, whereinthe residual carboxylic anhydride has a formula selected from the groupof;

where R³ is a divalent hydrocarbon group, and R⁴ is a hydrogen atom oralkyl group.
 5. The organopolysiloxane-modified polysaccharide accordingto claim 1, wherein the half ester group has a formula selected from thegroup of;

where R³ is a divalent hydrocarbon group, and R⁴ is a hydrogen atom oralkyl group.
 6. The organopolysiloxane-modified polysaccharide accordingto claim 1, wherein component (B) is selected from the group of ligneouspolysaccharides, polysaccharides obtained from fruit flesh and rhizome,plant adhesive substances, legume-derived polysaccharides,seaweed-derived polysaccharides, microorganism-produced polysaccharides,polysaccharides of animal origin, or a derivative of thesepolysaccharides.
 7. A process for the preparation oforganopolysiloxane-modified polysaccharide, said process comprising thestep of esterification reacting; (A) an organopolysiloxane havingresidual carboxylic anhydride groups, and (B) a polysaccharide havinghydroxyl groups, in the presence of (C) a non-protonic polar solvent. 8.The process for the preparation of organopolysiloxane-modifiedpolysaccharide according to claim 7, wherein component (A) is anorganopolysiloxane having the formula, R¹ _(a)R² _(b)SiO_((4-a-b)/2)where R¹ is a monovalent organic group containing a residual carboxylicanhydride, R² is a hydrogen atom or monovalent hydrocarbon group withthe proviso that at least one R² is a monovalent hydrocarbon when b isgreater than 1, and the subscripts “a” and “b” are numbers satisfyingthe conditions 0<a≦1, and 0<b≦3, respectively, and 0<a+b<4.
 9. Theprocess for the preparation of organopolysiloxane-modifiedpolysaccharide according to claim 7, wherein component (A) is anorganopolysiloxane having the formula selected from the group of;

where R¹ is a monovalent organic group containing a residual carboxylicanhydride group, R² is a hydrogen atom or monovalent hydrocarbon group,with the proviso that at least one R² is a monovalent hydrocarbon, n isan integer greater than zero, and c is an integer from 1 to
 4. 10. Theprocess for the preparation of organopolysiloxane-modifiedpolysaccharide according to claim 8, wherein the residual carboxylicanhydride has a formula selected from the group of;

where R³ is a divalent hydrocarbon group, and R⁴ is a hydrogen atom oralkyl group.
 11. The process for the preparation oforganopolysiloxane-modified polysaccharide according to claim 7, whereincomponent (B) is selected from the group of ligneous polysaccharides,polysaccharides obtained from fruit flesh and rhizome, plant adhesivesubstances, legume-derived polysaccharides, seaweed-derivedpolysaccharides, microorganism-produced polysaccharides, polysaccharidesof animal origin, or a derivative of these polysaccharides.
 12. Theprocess for the preparation of organopolysiloxane-modifiedpolysaccharide according to claim 7, wherein component (C) isN,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, orhexamethylphosphortriamide.
 13. The organopolysiloxane-modifiedpolysaccharide according to claim 1, wherein components (A) and (B) areesterfication reacted in the presence of (C) a non-protonic polarsolvent.
 14. The organopolysiloxane-modified polysaccharide according toclaim 13, wherein component (C) is N,N-dimethylacetamide,N,N-dimethylformamide, dimethyl sulfoxide, orhexamethylphosphortriamide.
 15. The process for the preparation oforganopolysiloxane-modified polysaccharide according to claim 7, whereinthe organopolysiloxane is bonded to the polysaccharide through halfester groups.
 16. The process for the preparation oforganopolysiloxane-modified polysaccharide according to claim 15,wherein the half ester group has a formula selected from the group of;

where R³ is a divalent hydrocarbon group, and R⁴ is a hydrogen atom oralkyl group.